Voice control device and voice control method

ABSTRACT

A voice control device and a corresponding voice control method are provided. The voice control device includes a sound receiver, a sound converter, a voice identifier, and a central processing unit (CPU). The sound receiver receives a first sound signal. The sound converter converts the first sound signal from analog signal to digital signal. The voice identifier identifies a first voice signal from the first sound signal, performs a first comparison on the first voice signal and a second voice signal, and generates a wake-up signal according to the first comparison. When receiving the wake-up signal, the CPU enters a working state from a sleeping state, performs a second comparison on the first voice signal and the second voice signal, and takes over the voice input from the sound receiver and the sound converter according to the second comparison.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of China application serialno. 201210491178.1, filed on Nov. 27, 2012. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND

1. Technical Field

The invention relates to a voice control device and a voice controlmethod. Particularly, the invention relates to a method of waking up avoice control device by using a predetermined phrase.

2. Related Art

Presently, more and more electronic devices start to use voice control,and the voice control will become a commonly used user interface of mostof the electronic devices.

However, regarding a mobile electronic device powered by batteries,energy consumption of a voice engine is rather high. To keep the voiceengine of the system being always in a running state may quickly consumeelectric energy of the system. Therefore, the voice engine of thepresent mobile electronic device is generally triggered by using abutton or a similar mechanism.

As the voice control is started by pressing a button, it is inconvenientfor the user to use. If the voice engine is kept to be activated, it maycause unnecessary energy consumption.

SUMMARY

The invention is directed to a voice control device and a voice controlmethod, by which a voice function is easily activated, and low powerconsumption is maintained in normal times, so as to resolve acontradiction of engine start and energy consumption.

The invention provides a voice control device including a soundreceiver, a sound converter, a voice identifier, and a centralprocessing unit (CPU). The sound receiver receives a first sound signal.The sound converter is coupled to the sound receiver and converts thefirst sound signal from analog signal to digital signal. The voiceidentifier is coupled to the sound converter, and identifies a firstvoice signal from the first sound signal, performs a first comparison onthe first voice signal and a second voice signal, and generates awake-up signal according to the first comparison. The CPU is coupled tothe sound converter and the voice identifier, and when the CPU receivesthe wake-up signal, the CPU enters a working state from a sleepingstate, performs a second comparison on the first voice signal and thesecond voice signal, and takes over a voice input from the soundreceiver and the sound converter according to the second comparison.

In invention provides a voice control method, which is adapted to avoice control device, and the voice control method includes followingsteps. A first sound signal is received. A first voice signal isidentified from the first sound signal. A first comparison on the firstvoice signal and a second voice signal is performed, and a wake-upsignal is generated according to the first comparison. In response tothe wake-up signal, a central processing unit of the voice controldevice enters a working state from a sleeping state, performs a secondcomparison on the first voice signal and the second voice signal, andtakes over a voice input of the voice control device according to thesecond comparison.

In order to make the aforementioned and other features and advantages ofthe invention comprehensible, several exemplary embodiments accompaniedwith figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a schematic diagram of a voice control device according to anembodiment of the invention.

FIG. 2A is a flowchart illustrating a voice control method according toan embodiment of the invention.

FIG. 2B is a diagram illustrating a signal transmission flow of thevoice control device of FIG. 1 corresponding to the method flow of FIG.2A.

FIG. 3A is a flowchart illustrating a voice control method according toan embodiment of the invention.

FIG. 3B is a diagram illustrating a signal transmission flow of thevoice control device of FIG. 1 corresponding to the method flow of FIG.3A.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

FIG. 1 is a schematic diagram of a voice control device 100 according toan embodiment of the invention. The voice control device 100 can be anymobile electronic device, for example, a mobile phone, a personaldigital assistant, a tablet computer, a notebook computer, or anyelectronic device as a desktop computer, etc. that is capable of beingcontrolled by voice. The voice control device 100 includes a soundreceiver 110, a sound converter 120, a voice identifier 130, and acentral processing unit (CPU) 140. The sound converter 120 is coupled tothe sound receiver 110, the voice identifier 130 is coupled to the soundconverter 120, and the CPU 140 is coupled to the sound converter 120 andthe voice identifier 130.

The voice control device 100 of the present embodiment can activate avoice control function thereof through a predetermined voice. In brief,the sound receiver 110 captures all sounds of the ambient environmentincluding a sound sent by the user, and outputs captured sound signals.The sound receiver 110 can be a microphone or a similar sound receivingdevice. The sound converter 120 converts the sound signal from analogsignal to digital signal. The voice identifier 130 and the CPU 140compare the sound signal with another predetermined sound signal todetermine whether or not to activate the voice control function of thevoice control device 100.

FIG. 2A is a flowchart illustrating a voice control method according toan embodiment of the invention, which relates to setting of apredetermined voice used for activating the voice control device 100,and the method is adapted to be executed by the voice control device100. FIG. 2B is a diagram illustrating a signal transmission flow of thevoice control device 100 corresponding to the method flow of FIG. 2A.

The predetermined voice is generally a short word or a phrase, forexample, a short watchword or password. Alternatively, the voice controldevice 100 can be named, and the name of the voice control device 100can serve as the aforementioned predetermined voice. After the usertells the predetermined voice, in step 210, the sound receiver receivesa sound signal. The sound converter 120 converts the sound signal fromanalog signal to digital signal. The sound converter 120 can alsoamplify the sound signal, where the sound signal includes a voice of theuser and noise of the ambient environment. In step 220, the CPU 140identifies the predetermined voice signal (which is referred to as VSDhereinafter) of the user from the sound signal. Then, in step 230, theCPU 140 extracts a predetermined voice characteristic (which is referredto as VCD hereinafter) from the predetermined voice signal VSD. The CPU140 can store the predetermined voice signal VSD and the predeterminedvoice characteristic VCD. The CPU 140 can also transmit thepredetermined voice signal VSD to the voice identifier 130 for storage.The predetermined voice signal VSD is the predetermined voice used toactivate the voice control device 100.

FIG. 3A is a flowchart illustrating a voice control method according toan embodiment of the invention, which relates comparison of theaforementioned predetermined voice, and the method is adapted to beexecuted by the voice control device 100. FIG. 3B is a diagramillustrating a signal transmission flow of the voice control device 100corresponding to the method flow of FIG. 3A.

First, in step 305, the voice control device 100 is in an initial state,i.e. the CPU 140 is in a sleeping state, and does not handle a voiceinput, while the voice identifier 130 in a working state handles thevoice input. The CPU 140 has the working state and the sleeping state,and the voice identifier 130 also has the working state and the sleepingstate. The working state refers to a normal working state, which hasnormal energy consumption. The sleeping state refers to a state ofnon-working and waiting to be woken up, which has very low powerconsumption.

Then, in step 310, the sound receiver 110 receives a sound signal, andthe sound converter 120 converts the sound signal from analog signal todigital signal. The sound converter 120 can also amplify the soundsignal, where the sound signal includes a voice of the user and noise ofthe ambient environment. In step 315, the voice identifier 130identifies an input voice signal (which is referred to as VSIhereinafter) of the user from the sound signal.

Then, in step 320, the voice identifier 130 performs a first comparisonon the input voice signal VSI and the predetermined voice signal VSD,and in step 325, the voice identifier 130 determines whether the twovoice signals match. If the input voice signal VSI does not match thepredetermined voiced signal VSD, the flow returns to the step 305. Ifthe input voice signal VSI matches the predetermined voiced signal VSD,in step 330, the voice identifier 130 generates a wake-up signal to wakeup the CPU 140.

In step 335, the CPU 140 receives the wake-up signal, and in step 340,the CPU 140 enters the working state from the sleeping state. The CPU140 receives the input voice signal VSI from the voice identifier 130,and in steps 345 to 365, the CPU 104 performs a second comparison on theinput voice signal VSI and the predetermined voice signal VSD. In thestep 345, the CPU 140 compares the input voice signal VSI and thepredetermined voice signal VSD, and in the step 350, the CPU 140determines whether the two voice signals match. If the input voicesignal VSI does not match the predetermined voiced signal VSD, the CPU140 re-enters the sleeping state, and the flow returns to the step 305.If the input voice signal VSI matches the predetermined voiced signalVSD, in step 355, the CPU 140 extracts an input voice characteristic(which is referred to as VCI hereinafter) from the input voice signalVSI, and in step S360, the CPU 140 compares the input voicecharacteristic VCI and the predetermined voice characteristic VCD, andin step 365, the CPU 140 determines whether the two voicecharacteristics match. If the input voice characteristic VCI does notmatch the predetermined voiced characteristic VCD, the CPU 140 re-entersthe sleeping state, and the flow returns to the step 305. If the inputvoice characteristic VCI matches the predetermined voiced characteristicVCD, in step 370, the CPU 140 takes over the voice input of the voicecontrol device 100, i.e. the voice input from the sound receiver 110 andthe sound converter 120. Now, the voice identifier 130 enters thesleeping state from the working state.

The CPU 140 executes a voice engine of the voice control device 100, sothat the step 370 is to activate the voice engine and the voice controlfunction of the voice control device 100.

Then, in step 375, the CPU 140 checks whether the CPU 140 does notidentify any voice signal from the voice input within a predeterminedtime after the CPU 140 enters the working state. If the CPU 140identifies the voice signal within the predetermined time, the flowreturns to the step 370, and if the CPU 140 does not identify any voicesignal within the predetermined time, it represents that the user doesnot send any voice command within the predetermined time, and the CPU140 re-enters the sleeping state, while the voice identifier 130re-enters the working state, and the flow returns to the step 305.

In the present embodiment, the voice identifier 130 and the CPU 140respectively perform comparison on the input voice signal VSI and thepredetermined voice signal VSD. Since the voice identifier 130 is a lowcost circuit with super low power consumption, an error identificationrate of the comparison thereof is higher than that of the CPU 140. Thesound receiver 110 has to continuously receive the sound signals, andthe voice identifier 130 has to identify the voice of the user from thecontinuous sound signals, which further increases the erroridentification rate of the voice identifier 130. Therefore, in thepresent embodiment, after the initial comparison of the voice identifier130, the CPU 140 again confirms the comparison. The CPU 140 has highercomputation capability, which can compare the input voice signal VSI andthe predetermined voice signal VSD by using a more accurate algorithm,so as to decrease the error identification rate.

In the present embodiment, comparison of the voice signals is used toconfirm that the user speaks the correct predetermined voice, andcomparison of the voice characteristics is used to confirm the users'identity since the voice characteristic of each person is different. Bycomparing the voice characteristics, only the specific user can activatethe voice engine of the voice control device 100, and if the user'sidentify is unnecessary to be limited, the step 230 of FIG. 2A and thesteps 355 to 365 of FIG. 3A are omitted. In this case, if the result ofthe step 350 is affirmative, the flow directly enters the step 370.

The voice identifier 130 is a simplified voice identification enginewith a low power consumption, which is specifically used to identify apredetermined short voice, and when the predetermined voice isidentified, the voice identifier 130 activates the CPU 140 to execute aformal voice engine. The voice identifier 130 is only required toperform a pronunciation match of a single short voice without using anacoustic dictionary and a language model, such that a scale and powerconsumption thereof is far less than that of a normal voiceidentification engine. In this way, not only very low stand-by powerconsumption is achieved, but also the user can directly active the voicecontrol through voice, such that the voice control device is easier touse and is more convenient. Therefore, a contradiction of voice enginestart and energy consumption is resolved.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of theinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the invention covermodifications and variations of this invention provided they fall withinthe scope of the following claims and their equivalents.

What is claimed is:
 1. A voice control device, comprising: a soundreceiver, receiving a first sound signal; a sound converter, coupled tothe sound receiver, and converting the first sound signal from analogsignal to digital signal; a voice identifier, coupled to the soundconverter, and identifying a first voice signal from the first soundsignal, performing a first comparison on the first voice signal and asecond voice signal, and generating a wake-up signal according to thefirst comparison; and a central processing unit (CPU), coupled to thesound converter and the voice identifier, wherein when the CPU receivesthe wake-up signal, the CPU enters a first working state from a firstsleeping state, performs a second comparison on the first voice signaland the second voice signal, and takes over a voice input from the soundreceiver and the sound converter according to the second comparison. 2.The voice control device as claimed in claim 1, wherein when the voiceidentifier performs the first comparison and the first voice signalmatches the second voice signal, the voice identifier generates thewake-up signal.
 3. The voice control device as claimed in claim 1,wherein when the CPU performs the second comparison, the CPU receivesthe first voice signal from the voice identifier, and when the firstvoice signal matches the second voice signal, the CPU takes over thevoice input, and when the first voice signal does not match the secondvoice signal, the CPU re-enters the first sleeping state.
 4. The voicecontrol device as claimed in claim 3, wherein the sound receiverreceives a second sound signal, the sound converter converts the secondsound signal from analog signal to digital signal, and the CPUidentifies the second voice signal from the second sound signal andtransmits the second voice signal to the voice identifier.
 5. The voicecontrol device as claimed in claim 4, wherein the sound converteramplifies the first sound signal and the second sound signal.
 6. Thevoice control device as claimed in claim 4, wherein the CPU extracts asecond voice characteristic from the second voice signal, and when theCPU performs the second comparison and the first voice signal matchesthe second voice signal, the CPU extracts a first voice characteristicfrom the first voice signal and compares the first voice characteristicwith the second voice characteristic; when the first voice signalmatches the second voice signal and the first voice characteristicmatches the second voice characteristic, the CPU takes over the voiceinput; and when the first voice signal does not match the second voicesignal or the first voice characteristic does not match the second voicecharacteristic, the CPU re-enters the first sleeping state.
 7. The voicecontrol device as claimed in claim 1, wherein when the CPU takes overthe voice input, the voice identifier enters a second sleeping statefrom a second working state.
 8. The voice control device as claimed inclaim 7, wherein when the CPU does not identify any voice signal fromthe voice input within a predetermined time after the CPU enters thefirst working state, the CPU re-enters the first sleeping state, and thevoice identifier re-enters the second working state.
 9. A voice controlmethod, adapted to a voice control device, and comprising: receiving afirst sound signal; identifying a first voice signal from the firstsound signal; performing a first comparison on the first voice signaland a second voice signal, and generating a wake-up signal according tothe first comparison; and in response to the wake-up signal, a centralprocessing unit (CPU) of the voice control device entering a workingstate from a sleeping state, performing a second comparison on the firstvoice signal and the second voice signal, and taking over a voice inputof the voice control device according to the second comparison.
 10. Thevoice control method as claimed in claim 9, wherein the step ofperforming the first comparison comprises: generating the wake-up signalwhen the first voice signal matches the second voice signal.
 11. Thevoice control method as claimed in claim 9, wherein the step ofperforming the second comparison comprises: the CPU taking over thevoice input when the first voice signal matches the second voice signal;and the CPU re-entering the sleeping state when the first voice signaldoes not match the second voice signal.
 12. The voice control method asclaimed in claim 11, further comprising: receiving a second soundsignal; and identifying the second voice signal from the second soundsignal.
 13. The voice control method as claimed in claim 12, furthercomprising: extracting a second voice characteristic from the secondvoice signal, and the step of performing the second comparison furthercomprises: extracting a first voice characteristic from the first voicesignal and comparing the first voice characteristic with the secondvoice characteristic when the first voice signal matches the secondvoice signal; the CPU taking over the voice input when the first voicesignal matches the second voice signal and the first voicecharacteristic matches the second voice characteristic; and the CPUre-entering the sleeping state when the first voice signal does notmatch the second voice signal or the first voice characteristic does notmatch the second voice characteristic.
 14. The voice control method asclaimed in claim 9, further comprising: the CPU re-entering the sleepingstate when the CPU does not identify any voice signal from the voiceinput within a predetermined time after the CPU enters the workingstate.